sqlalchemy.exc.IntegrityError: (sqlite3.IntegrityError) UNIQUE constraint failed: book.isbn when parsing and inserting csv data into database

Question

我对整个 flask/sqlalchemy 框架还很陌生，所以我想寻求一些帮助来找出我的烧瓶应用程序有什么问题。据我所知，我已经完成了主要的关键关系，因为它们应该是一对多的，从书到评论。请提供任何形式的帮助，在此先感谢！我在下面插入了我的代码以供进一步参考。

main.py

with open('books.csv', newline='') as csvfile:
    reader = csv.DictReader(csvfile)
    
    for row in reader:
        book = Book(isbn=row['ISBN'],title=row['Book-Title'], author=row['Book-Author'],
        publication_year=row['Year-Of-Publication'], publisher=row['Publisher'])
        db.session.add(book)
        db.session.commit()


print('database initialized!')

models.py

class Review(db.Model):
  id = db.Column(db.Integer, primary_key=True)      
  text=db.Column(db.String)
  rating=db.Column(db.Integer)     
  book=db.Column(db.String,db.ForeignKey("book.isbn"))

  def toDict(self):
    return {
      "id": self.id,
      "text": self.text,
      "rating": self.rating,
      "isbn": self.isbn
    }

class Book(db.Model):
  isbn=db.Column(db.String, primary_key=True)
  title=db.Column(db.String)
  author=db.Column(db.String)
  publication_year=db.Column(db.String)
  publisher=db.Column(db.String)
  reviews = db.relationship('Review', backref='book_review',lazy=True, cascade="all, delete-orphan")
  
  def toDict(self):
    return {
      "isbn": self.isbn,
      "title": self.title,
      "author": self.author,
      "publication_year": self.publication_year,
      "reviews": self.reviews
    }

Answer 1

插入 table 时唯一约束失败发生在您尝试插入的行的值来自具有 UNIQUE 属性的列与具有相同值的现有数据冲突时。要解决此问题，如果要插入空 table，您可以编辑 CSV 文件并使用 find 或其他选项来定位重复值。如果 table 有现有数据，我建议创建一个临时的 table 而无需为所述列定义 PK/UNIQUE。然后填充来自两个来源的数据。接下来，运行像这样的语句来查找重复值：

select problematic_column, count(problematic_column) ct from temporary_table 
group by problematic_column having ct>1 ;

sqlalchemy.exc.IntegrityError: (sqlite3.IntegrityError) UNIQUE constraint failed: book.isbn when parsing and inserting csv data into database

sqlalchemy.exc.IntegrityError: (sqlite3.IntegrityError) UNIQUE constraint failed: book.isbn when parsing and inserting csv data into database

python

mysql

jinja2

flask-sqlalchemy